Sound intensity level or acoustic intensity level is a logarithmic measure of the sound intensity (measured in W/m2), in comparison to a reference level.
The measure of a ratio of two sound intensities is
where I1 and I0 are the intensities.
The sound intensity level is given the letter "LI" and is measured in "dB". The decibel is a dimensionless quantity.
If I0 is the standard reference sound intensity
(W = watt), then instead of "dB SPL" we use "dB SIL". (SIL = sound intensity level).
Read more about this topic: Sound Intensity
Famous quotes containing the words sound, intensity and/or level:
“Midnight has come and the great Christ Church bell
And many a lesser bell sound through the room;
And it is All Souls’ Night.
And two long glasses brimmed with muscatel
Bubble upon the table. A ghost may come;
For it is a ghost’s right....”
—William Butler Yeats (1865–1939)
“The bourgeois treasures nothing more highly than the self.... And so at the cost of intensity he achieves his own preservation and security. His harvest is a quiet mind which he prefers to being possessed by God, as he prefers comfort to pleasure, convenience to liberty, and a pleasant temperature to that deathly inner consuming fire.”
—Hermann Hesse (1877–1962)
“It is only for a little while, only occasionally, methinks, that we want a garden. Surely a good man need not be at the labor to level a hill for the sake of a prospect, or raise fruits and flowers, and construct floating islands, for the sake of a paradise. He enjoys better prospects than lie behind any hill. Where an angel travels it will be paradise all the way, but where Satan travels it will be burning marl and cinders.”
—Henry David Thoreau (1817–1862)